GitLab

Move them from internal histograms.xml to chromium.org histograms.xml since they are/were referenced only in chromium.org code.

BUG=none

Review URL: https://codereview.chromium.org/449913002

Cr-Commit-Position: refs/heads/master@{#288370}
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@288370 0039d316-1c4b-4281-b951-d872f2087c98